Resin erecting lens array and method for fabricating the same

Abstract

A resin erecting lens array is fabricated by forming a coating of silicon dioxide compound on the surface of each of molded resin lens plates, forming an aperture stop for each micro-lens on the surface of each resin lens plate, applying an adhesive on end portions of each resin lens plate, spreading out the adhesive into the space between the resin lens plates being placed on top of one another, aligning an optical axis of each micro-lens on the resin lens plates, inserting heat-melting resin pins into the pin-insert holes of the resin lens plate, and melting at least one end of each resin pin to secure the resin lens plates together.

What is claimed is:  
     
       1. A method for fabricating a resin erecting lens array constructed of two or more resin lens plates being placed on top of one another, wherein each of resin lens plate is formed by an injection molding and is provided as a plate on which spherical or aspherical micro-lenses are arranged at established intervals, comprising the steps of: 
       forming an aperture stop for a spherical or aspherical surface of each lens on the surface of the resin lens plate;  
       applying an adhesive on protruded portions and in recessed portions on the end portions of the resin lens plate;  
       spreading out the adhesive into the space between the adjacent resin lens plates;  
       aligning an optical axis of each lens of the two or more resin plates; and  
       hardening the adhesive.  
     
     
       2. A method for fabricating a resin erecting lens array as claimed in  claim 1 , comprising a further step of: 
       forming a hydrophilic film on at least an adhesive-applied portion on the surface of the resin lens plate before or after the step of forming the aperture stop for a spherical or aspherical surface of each lens on the surface of the resin lens plate.  
     
     
       3. A method for fabricating a resin erecting lens array constructed of two or more resin lens plates being placed on top of one another, where each of the resin lens plate is formed by an injection molding and is provided as a plate on which spherical or aspherical micro-lenses are arranged at established intervals, comprising the steps of: 
       forming an aperture stop for a spherical or aspherical surface of each lens on the surface of the resin lens plate;  
       applying an adhesive on protruded portions and in recessed portions formed on the end portions of the resin lens plate;  
       spreading out the adhesive into the space between the adjacent resin lens plates;  
       aligning an optical axis of each lens of the two or more resin lens plates;  
       hardening the adhesive; and  
       inserting heat-melting resin pins into the pin-insert holes of the resin lens plates, which are formed In the predetermined positions on the end portions of the resin lens plate, and melting at least one end of each resin pin.  
     
     
       4. A method of fabricating a resin erecting lens array as claimed in  claim 3 , comprising a further step of: 
       forming a hydrophilic film on at least an adhesive-applied portion on the surface of ht resin lens plate before or after the step of forming the aperture stop for a spherical or aspherical surface of each lens on the surface of the resin lens plate.  
     
     
       5. A method for fabricating a resin erecting lens array constructed of two or more resin lens plates being placed on top of one another, where each resin lens plate is formed by an injection molding and is provided as a plate on which spherical or aspherical micro-lenses are arranged at established intervals, comprising the steps of: 
       forming an aperture stop for a spherical or aspherical surface of each lens on the surface of the resin lens plate;  
       aligning an optical axis of each lens of the two or more resin lens plates; and  
       inserting heat-melting resin pins into the pin-insert holes of the resin lens plates, which are formed in the predetermined positions of the end portions of the resin lens plate, and melting at least one end of each resin pin.  
     
     
       6. A method for fabricating a resin erecting lens array as claimed in one of claims  1 - 4 , wherein 
       a photo-curing adhesive is used as the adhesive to minimize displacements of the resin lens plates to be caused by deformations In the resin lens plates before or after the adhesion.  
     
     
       7. A method for fabricating a resin erecting lens array as claimed in one of  claims 1  to  5 , comprising a further step of: 
       forming a low reflective film on at least a part of the surface of the resin lens plate before or after the step of forming the aperture stop for a spherical or aspherical surface of each lens on the surface of the resin lens plate.  
     
     
       8. A method for fabricating a resin erecting lens array as claimed in one of  claims 1  to  5 , comprising a further step of: 
       sandwiching a light-blocking film in which openings are formed at the positions corresponding to arrangement of lenses or a light-blocking film on which openings are printed at the positions corresponding to the arrangement of lenses between at least a pair of the resin lens plates at the time of placing two or more resin lens plates on top of one another.  
     
     
       9. A method for fabricating a resin erecting lens array constructed of two or more resin lens plates being placed on top of one another, where each of resin lens plate is formed by an injection molding and is provided as a plate on which spherical or aspherical micro-lenses are arranged at established intervals, comprising the steps of: 
       inserting heat-melting resin pins into the pin-insert holes formed on the end portions of one of the resin lens plates at the time of placing two or more resin lens plates on top of one another; and  
       placing another resin lens plate on the resin lens plate using the resin pins as guide members.  
     
     
       10. A method for fabricating a resin erecting lens array constructed of two or more resin lens plates being placed on top of one another, where each of resin lens plate is formed by an injection molding and is provided as a plate on which spherical or aspherical micro-lenses are arranged at established intervals, comprising the steps of: 
       inserting heat-melting resin pins into the pin-insert holes formed at the predetermined positions of the end portions of each of the resin lens plates at the time of placing two or more resin lens plates on top of one another; and  
       melting at least one end of each of the resin pins, followed by application of pressure on both ends of each of the resin pins to mechanically hold the reins lens plates together.  
     
     
       11. A method for fabricating a resin erecting lens array as claimed in  claim 1 ,  3 ,  5 ,  9  or  10 , wherein 
       the adjacent resin lens plates are placed on top of one another in such a manner that differences between warped shapes of the opposite surfaces of the adjacent resin lens plates are small proximate to the center of each of the adjacent resin lens plates, compared with other portions.  
     
     
       12. A method for fabricating a resin erecting lens array as claimed in  claim 1 ,  3 ,  5 ,  9  or  10 , wherein 
       the resin lens plates are placed on top of one another by performing directional alignment using pin marks which are one of impressions caused by ejector pins which eject a molded body from a die when an injection molding process is complete, and gate marks which are impressions of the gate for injecting an injections molding resin into the die at the time of placing two or more resin lens plates on top of one another.  
     
     
       13. A resin plate formed by an injection molding, where spherical or aspherical micro-lenses are arranged on a plate at established intervals, wherein 
       pin-insert holes are formed in end portions through which heat-melting resin pins can be inserted for mechanically securing two or more resin lens plates together.  
     
     
       14. A resin plate formed by an injection molding, where spherical or aspherical micro-lenses are arranged on a plate at established intervals, wherein recessed and protruded portions are formed on end portions for increasing the contact area of an adhesive and, wherein the height of the protrusion in each of the recessed and protruded portions is lower than the height of the micro-lens. 
     
     
       15. A resin lens plate as claimed in  claim 13  or  14 , wherein 
       an aperture stop is formed for a spherical or aspherical surface of each micro-lens.  
     
     
       16. A resin lens plate as claimed in  claim 13  or  14 , wherein 
       a low reflective film is formed on the surface of the resin lens plate, and an aperture stop is formed in the low reflective film for a spherical or aspherical surface of each micro-lens.  
     
     
       17. A resin lens plate as claimed  claim 13  or  14 , wherein 
       a hydrophilic film is formed on at least a part of the surface of the uppermost layer.  
     
     
       18. A resin erecting lens array, wherein 
       two or more resin lens plates of one of  claim 13  or  14  are combined together.  
     
     
       19. A resin erecting lens array as claimed in  claim 18 , wherein 
       an aperture stop is formed for a spherical or aspherical surface of each micro-lens on at least one surface of the resin lens plate.  
     
     
       20. A resin erecting lens array as claimed in  claim 18 , wherein 
       a light-blocking film in which openings are formed at the positions corresponding to the arrangement of lenses or a light-blocking film on which openings are printed at the positions corresponding to the arrangement of lenses is sandwiched between at least one pair of resin lens plates.  
     
     
       21. A resin erecting lens array as claimed in  claim 18 , wherein 
       two or more resin lens plates are secured together using an adhesive applied on recessed and protruded portions formed on end portions of each resin lens plate.  
     
     
       22. A resin erecting lens array as claimed in  claim 18 , wherein 
       two or more resin lens plates are secured together using heat-melting resin pins being inserted into pin-insert holes formed at the predetermined positions of end portions of each resin lens plate.  
     
     
       23. A resin erecting lens array as claimed in  claim 18 , wherein 
       two or more resin lens plates are secured together using an adhesive applied on recessed and protruded portions formed on end portions of each resin lens plate and using heat-melting resin pins being inserted into pin-insert holes formed at the predetermined positions of end portions of each resin lens plate.  
     
     
       24. A resin lens plate formed by an injection molding as claimed in  claim 13  or  14 , further comprising: 
       a groove extending from a lens-forming region to a side of the resin lens plate is formed for keeping the pressure In the opposite lens-forming regions at the atmospheric pressure at the time of constructing a resin erecting lens array by placing two or more resin lens plates on top of one another.